F4V is a well-known flash video format developed by Adobe System. It is supported by Adobe Flash Player. Currently, approximately 80% of online videos are transmitted using Adobe Flash technology. Files with the F4V extension are called a container format. The F4V format, in comparison with other files of the FLV category, uses boxes to store information. In addition to devices with an operating system from Apple, these files can play almost all browsers that support flash video playback. F4V files resemble .FLV files, but use “blocks” to store data. Examples of blocks that are supported by the F4V format include meta block (metadata), moov block (file header), ftyp block (requested player tools), uda block (user data in free form), etc. The format container, in the development of which the ISO Media File Format was used, initially used the Quick Time Container Format from Apple. Compared to the old FLV format, the F4V format is fully compatible with the h.264 and ACC formats. This provides an opportunity to use other container formats.
KAR is the original format of audio files for creating karaoke, which are formed in a variety of software systems. It has the ability to save not only MIDI file data, but also lyrics. The KAR format is part of the .midi extension. In most cases, they are used as a source for adding special text to regular MIDI files, and they also differ from the Karaoke file. After all, there is no additional track with words that are synchronized with the main melody according to certain algorithms. As a rule, in order to realize the vocal part, you must apply the first track. For a stream of words, a second track is used. This file extension can be obtained using specialized software. But not only. It can also be created using MIDI keyboards that are connected to computer hardware. If there are appropriate plugins, then you can open the KAR file using the Media Player traditional for the Windows operating system. Anyone using the Mac OS platform can play KAR files in the Mireth Technology Music Man karaoke application. But the universal option for this pair of systems is PG Music Band-in-a-Box. This software is the most popular among analogues. Together with the .KAR extension, they sometimes provide reference data on where audio catalogs and item metadata associated with audio tracks are located. It is also possible that there is information about the artist and about the albums.